It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention. Further, the discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art problems by the inventor. Moreover, any discussion of material such as documents, devices, acts or knowledge in this specification is included to explain the context of the invention in terms of the inventor's knowledge and experience and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein.
Enrichment of the environment in which an animal lives is essential to their physical and psychological health and wellbeing, particularly for domestic and captive animals. This is as important for captive zoo animals as it is for domestic pets such as dogs. Conscientious animal carers provide animal enrichment by providing opportunities for exercise, satisfying their ‘behavioural needs’ and optimising the level of stimulation they receive. Animals that do not have adequate enrichment can develop abnormal behaviours. For example, a bored dog will seek and find ways to amuse themself that will be viewed as a nuisance by their owner and neighbours, including pulling and chewing washing on a clothesline, barking or digging up plants in a garden. This type of behaviour, in combination with call outs to the local council or animal authorities and the need for conflict resolution with neighbours often prompts owners to provide enrichment for their dogs. The problem is exacerbated by increasing numbers of animals living in confined spaces over long periods within medium and high density apartments.
Examples of enrichment provided by owners of domestic animals include:                a. A digging pit for hiding bones, treats or favourite toys to encourage digging in a chosen location;        b. A wading pool, particularly for water loving dogs;        c. Ice blocks with favourite treats or toys in them;        d. Treasure hunts comprising treats hidden around the yard for the pet to find;        e. Boxes enclosing food or toys, or arranged as obstacles;        f. A viewing area for the pet to see what is happening outside the yard; and/or        g. Toys such as KONG™, BUSTER CUBE™, HOME ALONE™ toys or feeder balls.        
Provision of dog toys is a particularly popular option but it is difficult to ensure that the dog's toys remain novel. Most owners have to remove them after a day and return them to the dog at a later time, such as in one week, so they remain new and exciting or alternatively provide the dog with different toys. Animal carers also have to be careful that the toy does not compromise their pet's safety and will not cause problems if consumed.
Accordingly a wide range of dog toys are available to take advantage of dogs' enjoyment of activities such as chasing, catching and pulling objects. These activities are often even more enjoyable if the object has eccentric or unpredictable motion.
For example, many dog toys are designed for tug-of-war, typically with an owner or another dog. These types of toys are disclosed for example in U.S. Pat. No. 5,092,272, U.S. Pat. No. 3,830,202 and U.S. Pat. No. 3,476,086.
Another type of dog toy utilises an object suspended from a post or frame on a rope or elastic cord. For example, dog toys of this type are disclosed in U.S. Pat. No. 5,575,241, U.S. Pat. No. 5,474,032, and U.S. Pat. No. 6,575,119. U.S. Pat. No. 6,575,119 discloses a suspended dog amusement apparatus, system and method for amusing and exercising dogs. The system is relatively complex, requiring a bar, a first suspension element for suspending the bar from a horizontal member at a support point on the bar, a weight element secured to the bar that applies a first gravitational torque to the bar about the support point and a second suspension element secured to the bar that comprises a strand-like member attached to a resilient dog toy and which produces a second gravitational torque to the bar about the support point. The suspended dog toy has random and unpredictable motion when touched.
A similar type of animal toy is disclosed in U.S. Pat. No. 7,900,584 which relates to a device having a moveable pendulum shaft secured within a housing, the pendulum being capable of carrying multiple toys, each toy being accessible through access openings in the housing.
Another type of dog toy relies upon odours, food or flavourings to hold the dog's interest. For example U.S. Pat. No. 6,546,896 relates to an animal toy having a plurality of irregular features on the outer surface which stimulates cleaning of the dog's teeth and gums, and allows food treats to be placed in the irregular features.
However there is an ongoing need for new durable animal toys that engage an animal in stimulating activities that substitute for the lack of interaction and stimulation that can contribute to abnormal and/or destructive behaviour.